8891/0 Epithelioid leiomyoma




Corpus uteri
ICD-O-3 topography code: C54

Epithelioid leiomyoma is a histological variant of leiomyoma composed of round to polygonal epithelial-like cells which are arranged in clusters or cords. Three subtypes of epithelioid leiomyoma are distinguished: leiomyoblastoma, clear cell leiomyoma and plexiform leiomyoma. Mixtures of different patterns within the same tumour are common.
Small tumours without cytological atypia, necrosis or elevated mitotic figures are benign. Circumscribed margins, extensive hyalinization and a predominance of clear cells generally also indicate benign behaviour. Potentially malignant are tumours with two or more of the following features: large size (>6cm), moderate mitotic activity, moderate to severe cytological atypia, and necrosis. In these cases, careful follow-up is necessary1
Tavassoli FA, Devilee P (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Breast and Female Genital Organs.
3rd Edition
IARC Press: Lyon 2003